class Evente{
    constructor()
    {
        this.map = {};
    }
    add(name, fn)
    {
        if (this.map[name]){
            this.map[name].push(fn)

            return
        }
        this.map[name] = [fn]
        return;
    }
    emit(name,...args){
        this.map[name].forEach(fn=>{
            fn(...args);
        })
    }
}
let e= new Evente();
e.add("hello",(err,name)=>{
    if(err){
        console.error(err)
        return
    }
    console.log(name)
})
e.emit('hello',"发生了错误")
e.emit("hello",null,"hellow nodejs")
